Kamuran Pamuk

Effect of Mg2SO4 usage on spinal cord ischemia-reperfusion injury: Electron microscopic and functional evaluation

Objectives: To evaluate the effects of intravenous magnesium sulfate (Mg2SO4) administration on ischemia-reperfusion injury of the spinal cord. Material and Methods: Sixteen rabbits were randomly assigned to the control (group I, 8 rabbits) and the study group (group II, 8 rabbits). The abdominal aorta was clamped for a period of 30 min followed by a reperfusion period of 60 min. The animals in group II received 0.25 ml/kg/h Mg2SO4 intravenous infusion (15% Mg2SO4) throughout this procedure. The animals were then observed for 24 h after which their neurological states were evaluated and tissue samples obtained from the spinal cord were examined with electron microscopy. Results: Aortic pressure distal to the cross-clamp during the occlusion period was 9 ± 3 mm Hg in group I and 19 ± 6 mm Hg in group II. All animals in group I were paraplegic at the end of the study. In group II the neurological outcome of 1 animal was poor while the other 7 animals were neurologically in a good condition. Electron microscopic examinations of the spinal cord tissues of group I revealed severe injury but the ultrastructure was well preserved in group II. Conclusions: Intravenous Mg2SO4 administration may have protective effects on the ischemia-reperfusion injury of the spinal cord. We propose that Mg2SO4 may be an additional protective pharmacological agent in thoracal and thoracoabdominal aortic surgery.

Implantation of Novel Small-Diameter Polyurethane Vascular Prostheses Interposed in Canine Femoral and Carotid Arteries

Objectives: The performance of small-diameter (3–5-mm) vascular grafts still poses a challenge in the field of vascular surgery. We present here our preliminary experience with implanting unique small-sized polycarbonate urethane vascular grafts in 7 dogs. Material and Methods: Each animal was implanted with 4 interposition grafts, 2 femoral and 2 carotid. No anti-thrombotic medication was administered. Doppler sonography was performed at 3-month intervals to examine for patency and flow characteristics. Animals were sacrificed electively at 3, 6 and 12 months. Results: At 3 months, all grafts were patent. After 6 months, 3 grafts occluded and at 1 year a further 6 grafts occluded. Hence 9 of 28 grafts occluded (67.9% patency). During the study, no correlation could be established between flow velocity or resistance index and occlusion. Histopathology showed intimal hyperplasia to be the cause of occlusion. Conclusions: Compared to literature data on small-diameter grafts in the same position, ADIAM’s Biomechanical grafts performed clearly better. Compliance data suggest a correlation between elastic compliance and patency.